Frank McCourt's The Irish...And How They Got That Way has settled into the Davis Square Theatre in Somerville for an eight-week run which concludes, appropriately, on St. Patrick's Day. Written by the Pulitzer Prize-winning author of Angela's Ashes, the fast-paced musical revue premiered at the Irish Repertory Theatre in New York in 1997 and previously played Boston in 1998. This production, under the direction of Danielle Paccione, features the 2010 Philadelphia cast of six multi-talented young men and women, all of whom play multiple instruments, sing, dance, and act, more or less in that order.

Music Director Jon Dykstra comes onstage whistling, taking swigs from a can of beer, and wearing a tweed cap and corduroys to evoke the first couple of Irish stereotypes that will be bandied about during the course of the evening. From his perch behind the keyboard, he leads his fellow players on their musical journey, performing more than two dozen songs to convey the history of the Irish across the 20th and 21st centuries. The telling is irreverent, buT Loving, often emotional, and sometimes bawdy. The musical numbers comprise lots of Irish folk ballads, war songs, patriotic paeans, and even something by Irish rock band U2.

As an ensemble, the three women and three men are cohesive, harmonize beautifully, and appear to be having fun in each other's company. Meredith Beck is a Kate Hudson lookalike capable of alternately singing sweetly or belting. Her flute playing enriches the musical sound otherwise provided by piano, strings, and percussion, and she does some nifty step dancing, as well. Andrew Crowe cavorts around the thrust stage like a leprechaun, and although his primary instrument is the violin, he takes turns on guitar, mandolin, percussion, and piano, contributing vocals at the same time. Dykstra steps out from behind the keyboard periodically to dance and play percussion, and he is a highlight in the enactment of "Finnegan's Wake."

There has to be an Irish tenor and Gregg Hammer takes the role, most affectingly with his soulful version of "Danny Boy." He is the resident jester, often hamming it up to draw our attention, and he anchors many of the songs on percussion, guitar, and harmonica. Auburn-haired Janice Landry sings beautifully and quietly displays both comic and dramatic flair. Her instruments are guitar, percussion, and piano. Irene Molloy plays the same three instruments, as well as mountain dulcimer, and has a strong voice with a broad range.

By way of background, the cast starts out by scathingly filleting the British, asserting that, "To understand the Irish, you have to understand the English." One of the easiest targets is their cooking, but they take a serious beating when some of the details of the potato blight are laid out. Essentially, most of the blame for the famine is laid at their feet, but the story is necessarily abridged because The Irish... has to cover a lot of ground. We are told that the international community, including the United States, provided unprecedented aid, but our shores were not as welcoming as they expected when the Irish came here for refuge and opportunity ("No Irish Need Apply"). Although they faced rampant discrimination in hiring, the immigrants showed valor and patriotism by their service in the Civil War.

Names of famous Irish-Americans from various walks of life are rattled off, but the ultimate Irish-American patriot was George M. Cohan who made his mark on Broadway. An arc of six of his songs ranges from "Give My Regards to Broadway" to his classic nationalistic tunes, "You're a Grand Old Flag," "Over There," and "Yankee Doodle Dandy." Of course, the latter was made famous by James Cagney, another great Irish-American performer who won an Oscar for Best Actor in the 1942 motion picture of the same name that depicted Cohan's life. Four members of the troupe are featured in some Vaudeville patter and a little song and dance, choreographed by Lexington native son Sebastian Goldberg.

The Irish...And How They Got That Way is at its best during the musical numbers. As ardent as the winning ensemble is, they can't really inhabit the experiences that they are recounting, and McCourt glosses over a rather large swath of history in a short amount of time. Also, their Irish accents come and go, occasionally sounding authentic, but that's just a quibble. The six performers maintain their energy throughout and close with a foot-stomping, drum-pounding rendition of U2's "Still Haven't Found What I'm Looking For." The audience was really into it and, despite its diversity, at that moment, everyone was Irish.